A software defined radio is exactly what its name suggests: a radio device whose operational characteristics are defined by its software rather than by its hardware. Components which are typically implemented in hardware such as filters, detectors, modulators/demodulators, are instead implemented with software for general purpose processors which can be executed on most personal computers. This provides the SDR huge flexibility with respect to operating frequencies, supported protocols, waveforms etc meaning that virtually anything can be implemented. Practical implementations of such devices have only recently become feasible due to the rapid advance in electronics. SDR has been deemed by many as the future of telecommunicatio

Who Uses GNU Radio?

I was once asked to justify expenditures on GNU Radio based projects. So, I began compiling a list of known GNU Radio projects, and I used this list to show that GNU Radio is of interest to a lot of folks who are doing interesting things. I created this list by reading the mailing list traffic, and writing down names associated with projects. I had plans to turn this list into a "Who's Who in GNU Radio" that would be put up on the wiki, and edited by the community to ensure correctness. Ideally, someone would build a database out of this information so that an interested party could search by technology or name or institution etc... However, I haven't had the time to do that.

I've attached the list with no guarantee of correctness. I hope it helps, but caveat emptor.

On Mon, 2006-10-09 at 16:10 +0800, Jeremy Chew wrote: My research group is new to GNU Radio and I like to know what groups out there are using this. I'm aware that there's the ORBIT testbed in Rutgers University and the work by University of Paderborn Computer Networks group. If you happen to know more or are aware of what websites are useful for me, please let me know.

Cognitive radio networks Vivek Raghunathan, BBN Tech.ADROIT Project getting GNU Radio to be able to receive and decode IEEE 802.11 frames and inject these frames into the NetBSD kernel networking stack.

Implementing a custom MAC protocol on a GNURadio-based network testbedSchools using GR/USRP

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MIT

Case Western Reserve

Notre Dame

Portland State

NCSU

Wright State

Virginia Tech

UCLA

University of Michigan

Univ. Illinois at Urbana Champaign

Univ. Illinois at Chicago

Telematik, Techn. University Graz, Austria

Univ. of Texas

University of Utah (USRP developed under NSF grant there)

Univ. of Deleware

Agencies using/funding GR/USRP

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DARPA AFR Radio Astronomy places NASA AMES

ns, as most devices are expected to be SDRs in the near future.

Current applications include the Joint Tactical Radio System (JTRS) of the US Army, as well as many amateur radio or home use applications, replacing the, much slower, computer sound cards which were used earlier. Certain implementations, such as the USRP which we will discuss below, are also widely used for academic and industrial research programs, due to the flexibility they provide in contrast to hardware transceivers.

Universal Software Radio Peripheral (USRP)

The USRP provides relatively cheap hardware for building a software defined radio. It has an open design, with schematics and drivers freely available. The GNU radio software project provides ready-to-use implementations of many well known analog and digital radio protocols, such as FM radio and digital television receivers. In terms of hardware, the USRP includes some high speed 14 bit digital-to-analog (DAC) and 12 bit analog-to-digital (ADC) converters, an Altera Cyclone FPGA, USB 2.0 interface and 4 extension sockets for daughterboards. These daughterboards cover some more specific needs. For example, transceivers operating at frequencies ranging from DC (0Hz) up to more than 4GHz are available, covering almost the whole usable radio spectrum.

Recent Developments

The USRP2 was introduced in 2008. This board has a Xilinx Spartan 3 FPGA, gigabit ethernet, higher resolution and faster DAC and ADC modules. Its drawback is that the software tools from Xilinx which are compatible with the Spartan FPGA are not available for free. It is important to note that this platform is not intended to replace the initial USRP, they are still sold in parallel. The HPSDR (High Performance Software Defined Radio) is a project that uses a 16-bit 135MSPS analog-to-digital converter (instead of 14-bit @ 100MSPS of the USRP2) that provides performance over the range 0 to 55 MHz comparable to that of a conventional analogue HF radio.